1. Field of the Invention
The present invention generally relates to apparatuses for removing buoyant pollutants, and more particularly, to an apparatus for removing buoyant pollutants from a polluted coolant.
2. Discussion of the Related Art
In order to prevent overheating of cutting tools, a coolant is generally applied to the cutting tool to cool it. However, when using the cutting tool, pollutants, such as oil, and debris, such as dust and other particles, may contaminate the coolant in a coolant tank. The oil generally floats atop the coolant. Some of the debris will mix with the coolant, some debris will sink to the bottom of the coolant, and some debris will mix with the oil and float atop the coolant. Because the majority of coolants for cutting tools are viscous, most of the debris will mix with the oil and float atop the coolant.
The coolant tank for receiving the coolant is generally badly ventilated. In badly ventilated environment, contamination of the coolant will increase and because most of the pollutants are buoyant this creates a haven for micro-organisms and the micro-organisms further contaminate the coolant. When the contaminated coolant is applied to the cutting tool, the cutting tool erodes and deteriorates, resulting in poor quality work-pieces machined by the cutting tool. In addition, the contaminated coolant may also be a health hazard. Therefore, the coolant must be changed periodically to prevent contamination. Changing the coolant increases costs and takes time, thus decreasing the work efficiency.
In order to extend the usage life of the coolant, the buoyant pollutants such as oil and debris floating atop a body of the coolant should be removed by an apparatus. There are mainly four typical kinds of apparatuses for removing buoyant pollutants from the coolant: a rubber-strip-type apparatus, a metal-strip-type apparatus, a swob-type apparatus, and a whirlpool-type apparatus. The rubber-strip-type apparatus includes a rubber strip for absorbing buoyant pollutants. The rubber-strip-type apparatus is stable for removing buoyant pollutants, but the usage life of the rubber strip is short and the efficiency is relatively low. The metal-strip-type apparatus includes a metallic strip for removing buoyant pollutants. The usage life of the metallic strip is relatively long, but the efficiency of the metallic strip is also relatively low. The swob-type apparatus includes a swob for absorbing buoyant pollutants. The efficiency of the swob-type apparatus is high, but the swob is easily damaged when there are a lot of impurities in the coolant. The whirlpool-type apparatus has a high efficiency, and also has a relative long usage life, but the whirlpool-type apparatus is easily clogged by impurities collected from the coolant.
Therefore, an apparatus that is less likely to be clogged by impurities and has high efficiency for removing buoyant pollutants, and to be stable over the long term, is desired.